Could someone clarify something for me please? I think I already know the answer but I just want to make sure. Myself a British citizen, my Thai wife and our 4 year old daughter want to visit the UK. Our daughter has a British and Thai passport. Can our daughter enter the UK using her British passport without the need for a UK visit visa or any additional paper work. Many thanks.

Yes.

Exit on the Thai passport, arrive UK on the British passport,

Great, thank you very much.